Crankshaft grinding machine



March 21, 1939. H. A. SILVEN CRANKSHAFT GRINDING MACHINE Fil ed Oct. 18, 1935 8 Sheets-Sheet l m @U @G HERBERT A. SH. l/EN March 21,- 1939. H. A. SILVEN 2,151,666

CRANKSHAFT GR INDI NG MACHINE Filed Oct. 18, 1935 s Sheets-Sheet 2 395 I82 3mm HERBERT A.S/LVEN W 2;zp naqgguo.a

twang March 21, 1939. H. A. SILVEN I CRANKSHAFT GRINDING MACHINE Filed Oct. 18, 1935 8 Sheets-Sheet 4 w w 4 4 m W w w a n Z 7 I I Iv w m 3 T z WW v I 4 n a 2 Ln M 2:37 I .n I a n 6 Z 7 f 6 7 6 3 a 3 Fl 9 9 0 7 Z Z A: w z z w 3 3 w 0 3 g am HERBERT A. S/LvE/v March 21, 1939. H, A. SILVEN C RANKSHAFT GRINDING MACHINE 8 Sheets-Sheet 5 Filed Oct. 18, 1955 HERBERT A. S/Ll/E/v V Gktovmm Filed Oct. 18, 1935 8 Sheets-Sheet 6 1114mm HERBERT A. S/Ll/EN Gum 114A;

March 21, 1939. H. SELVEN 2,151,666

CRANKSHAFT GR INDING MACHINE Filed Oct 18, 1935 8 Sheets-Sheet '7 /93 FIG. 24 z ERBERTA. SILVEN Patented Mar. 21, 1939 NITED STAT'ES 2,151,666 CRANKSHAFT GRINDING MACHINE Herbert A. Silven, Worcester, Mass., assignor to Norton Company, Worcester, Mass, a corporation of Massachusetts Application October 18, 1935, Serial No. 45,592

10 Claims.

This invention relates to grinding machines, and more particularly to a double head crankpin grinding machine.

One of the objects of this invention is to provide a simple, thoroughly practicable, readily controllable crankpin grinding machine. Another object is to provide a crankpin grinding machine with a single lever control which serves to control the various movements of the machine parts. Another object is to provide a crankpin grinding machine with a single'lever control which serves to control the table traverse, the forward and rearward feeding movement of the grinding wheel, the positioning movement of the steadyrest, and the work clamp release.

It is a further object to provide a crankpin grinding machine with a spark splitting mechanism for axially moving the grinding wheel spindle within its hearings to equalize the side grinding of the wheel.

This invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts as will be exemplified in the structure to be hereinafter described, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings, in which is shown one of various possible embodiments of the mechanical features of this invention,

Fig. 1 is a front elevation of a'crankpin grinding machine embodying this invention, having parts broken away and shown in section to more clearly show the construction;

Fig. 2 is a fragmentary piping diagram of the hydraulic system;

Fig. 3 is a transverse sectional view through the grinding machine, showing the wheel feeding mechanism for the grinding wheel slide and the jogging mechanism for the work table;

Fig. 4 is a fragmentary front elevation, on an enlarged scale, of the control mechanism on the front of the machine base;

Fig. 5 is an end elevation, partly in section, of the mechanism shown in Fig. 4;

Fig. 6 is a horizontal sectional view taken approximately on the line 6-6 of Fig. 5;

Fig. 7 is a fragmentary sectional view, on an enlarged scale, taken approximately on the line l--'I of Fig. i;

Fig. 8 is a fragmentary sectional view, showing the steadyrest and its operating mechanism;

Fig. 9 is a fragmentary vertical section, on an enlarged scale, of the work table jogging mechanism as shown in Fig. 3;

55 Fig. 10 is a fragmentary elevation, on an enlarged scale, of the jogging lever and. its supp Fig. 11 is a horizontal sectional view taken approximately on the line ll i-H of Fig. 2, showing the connection between the lower control valve and the main control lever;

Fig. 12 is a fragmentary detail view, on an enlarged scale, of the main control lever and limit switch operated thereby;

Fig. 13 is a fragmentary detail view, on an enlarged scale, of the interlock between the hydraulic table traverse and the manual jogging apparatus for the table;

Fig. 14 is a fragmentary sectional view, on an enlarged scale, taken approximately on the line i4-l4 of Fig..l3;

Fig. 15 is a fragmentary top plan View, partly in section, of the left-hand end of the parts shown in Fig. 13;

Fig. 16 is a fragmentary vertical sectional view of the cam and limit switch on the left-hand work head, taken approximately on the line lG--l6 of Fig. 1;

Fig. 17 is aleft-hand end elevation of the parts shown in Fig. 16;

Fig. 18 is an electric wiring diagram, showing the work stop control mechanism for stopping the rotation of the work holder in a predetermined position; i

Fig. 19 is a vertical longitudinal section through the wheel slide, showing the spark splitting mechanism for moving and positioning the grinding wheel;

Fig. 20 is a fragmentary sectional view, taken approximately on the line 20-20 of Fig. 19;

Fig. 21 is a fragmentary plan view, taken approximately on the line 2 I2l of Fig. 20;

Fig. 22 is a sectional view, on an enlarged scale, through the control valve, showing the valve in position during the loading of a work piece;

Fig. 23 is a similar sectional view through the valves when the lever is moved forward to clamp the crankshaft in place and the lever is moved toward the left to cause a fast traversing movement of the work table toward the left;

Fig. 24 is a similar sectional view through the valves positioned to cause a slow traversing movement of the table toward the left, with the steadyrest down and the wheel slide back;

Fig. 25 is asimilar sectional view through the control valves positioned to stop the work table when opposite the crankpin to be ground, with the steadyrest and the wheel slide in its rearward position;

Fig. 26 is a similar sectional view through the mounted on the control valves positioned so that the table is stopped opposite the crankpin to be ground and the wheel slide is moved forward while the steadyrest remains down in an inoperative position;

Fig. 27 is a similar sectional view through the control valve with the work table stopped in a grinding position and the wheel slide moved forward into a grinding position, and the steadyrest moved upward into an operative position with relation to the work; and

Fig. 28 is a fragmentary sectional view, on an enlarged scale, through the dashpot mechanism. A double head crankpin grinding machine has been illustrated in the drawings comprising a base 88 which supports a transversely movable wheel slide 8| carrying a rotatable grinding wheel 82 on a wheel spindle 38 Journaled in the slide 8 I The wheel slide 8| is arranged to slide transversely on ways 84 on the base 88. The grinding wheel may be rotated by any suitable source of power such as, for example, an electric inotor 86 upper surface of the wheel slide 88 is provided with a driving is connected by driving belt 81 mounted on the end of the wheel 8|. The motor pulley 86 which with a pulley 88 spindle 88.

A longitudinally movable work table 48 is arranged to slide longitudinally of the base 88 on a V-way 4| and a flat way 42. The work table 48 is provided with a rotatable work support which is preferably of a double head type comprising a pair of opposed base work heads 46 and 46 which in turn rotatably support work holders 41 and 48 respectively.

Work clamping and rotating The work supporting heads 41 and 48 (Figs. 1 and 2) are arranged to rigidly clamp a crankshaft therebetween and to synchronously rotate the opposite ends of the crankshaft. The work heads 41 and 48 have not been illustrated in detail since they do notconstitute a part of the present invention. For further details as to the construction of the heads 41 and 48, reference may be had to the prior U. S. patent to Silven and Belden No. 1,837,342 dated December 22, 1931. As illustrated in Fig. 1, the work head 46 has been shown broken away to illustrate the construction of the head. The work holder 48 is provided with a toggle 48 arranged to actuate the This toggle is actuated by a rod 88 mally urged toward the left, as viewed in Fig. 1, by means of a spring 6| within a rotatable work spindle 62. The spring II tends to move the rod 68 toward the left, as viewed in Fig. 1, to close the toggle and clamp the end of the crankshaft therein.

The head 46 and work holder 41 are provided with a similar spring actuated toggle clamping mechanism for the left-hand end of the crankshaft to be ground, comprising a rod 65 and a spring 56 (Fig. 2) which tends to urge the rod 65 toward the right, as viewed in Fig. 2, to clamp the left-hand end of a crankshaft rigidly in position in the work holder 41. The rod 66 and spring 86 are contained within the work rotating spindle I 81 which is rotatably supported in suitable bearings within the head 46.

The opposed work heads 41 and 48 are flxedly mounted on the inner ends of the work rotating spindles 61 and 62 respectively. The spindles I1 and 62 are rotated in synchronism with each other so that the shaft to be ground is gripped and rotated from its opposite end. An electric motor 68 is mounted within the base of the ma- 1 68 and 64 which chine. The motor 88 is connected by a link chain 6| to rotate a longitudinally extending shaft 62 mounted in bearings (not shown) 'within the base 88. The shaft 62 is provided with sprockets are connected by link chains 65 and 66 respectively with sprockets 61 and 68 which are fixedly mounted on the outer ends of the work rotating spindles 51 and 52 respectively to transmit and synchronously rotate the work supporting and gripping heads 41 and 48 respectively. It will be readily apparent from the foregoing disclosure that rotation of the motor 68 serves to synchronously rotate the work supporting and gripping heads at opposite ends of the crankshaft to be ground.

In order that the work may be released from the work heads 41 and 48, a fluid pressure mechanism is provided to simultaneously unclamp each of the work clamps to release the same and allow the ground piece of work to be removed and a new crankshaft to be inserted thereinstead. This mechanism comprises a cylinder 18 (Figs. 1 and 2) which is mounted adjacent to the lefthand end of head 45. A piston 1| is slidably mounted within the cylinder 18 and is connected to the rod 86. When fluid is admitted to a cylinder chamber 12, the piston 1| is moved, toward the left, as viewed in Fig. 2, to cause a corresponding movement of the rod 66 against the tension of the spring 66 to release the clamp on the left-hand work head 41.

A similar fluid pressure release is provided at the right-hand end of the machine, comprising a cylinder 16 having a piston 16 slidably mounted therein which is fixedly connected to the rod 66. When fluid under pressure is admitted to cylinder chamber 11, the piston 16 will be moved toward the right, as viewed in Figs. 1 and 2, to move the rod 88 in a corresponding direction to release the toggle 48 and thereby unclamp the right-hand end of the work piece.

Wheel feed The wheel slide 8| (Figs. 2 and 3) may be moved transversely to feed the grinding wheel toward or from the work piece manually by means of a nut and screw mechanism comprising a nut 88 depending from the wheel slide 8| which meshes with a feed screw 8| rotatably journaled in bearings 82 and 83. A gear 84 is mounted on the outer end of the feed screw 8| and meshes with a gear 85 mounted on the rear end of a rotatable shaft 86. The front end of the shaft86 is provided with a gear 81 meshing with a small gear 88 on the rear end of a rotatable shaft 88. The front end of the shaft 88 is provided with a gear 88 which meshes with a gear 8| rotatably mounted on a stud 82. The gear 8| meshes with a gear 88 which is formed integral with a manually operable hand wheel 84. The hand wheel 84 and gear 88 are rotatably mounted on a stud 86. By rotating the manually operable hand wheel 84, a

rotary motion is transmitted through the gear 88,

the gear 8|, the gear 88, the shaft 88, the gear 88, the gear 81, the shaft", the gear 85, the gear. 84, to rotate the feed screw 8| so as to cause a forward or rearward feeding movement of the wheel slide 8| and grinding wheel 82, depending upon the direction of rotation of the hand feed wheel 84.

In order that the rapidly toward or from the work piece to be ground, it is desirable to provide a fluid pressure mechanism which supplements the nut and screw grinding wheel may be moved feed and serves to rapidly move the grinding I" the piston rod 98. The piston wheel toward or from the work. In the preferred construction, the bearing 83 for the rear end of the feed screw is arranged in axial alignment with and connected to a piston rod- 98 which is connected'to a piston 98 slidably mounted within a fluid pressure cylinder I00. By admitting fluid to opposite ends of the piston rod, the feed screw 8| may be moved rapidly in an axial direction to cause a rapid approaching or receding movement of the wheel slide 3| and the grinding wheel 32. If desired, the hydraulic approach for the approaching and receding movement of the wheel.

may be supplemented by a dash pot mechanism to slow down the rapid approach of the grinding wheel to a suitable speed for grinding the opposed cheeksatopposite ends of the crankpin being ground. This may be accomplished by means of'amechanism such as that shown in a copending U. S. patent application Serial No. 669,565 of Herbert A. Silven filed May 5, 1933, which issuedas U. S. Patent No.- 2,023,704 dated December 10, 1935. Complete details of this feed have not been illustrated since reference may be had to the prior patent for details of disclosure. The piston rod 98 extends through the rear cylinder head of the cylinder I00. A dash pot piston.

I0| is slidably mounted on the extending end of IOIis surrounded by a dash pot cylinder-I02. The outer end of the piston rod 98 is provided with-an adjustable nut I03 which serves after a predetermined forward approaching movement of the wheel to engage and pick up the dash pot piston I0 I The fluid within the dash pot chamber I04 thereafter exhausts through a needle valve I05 which serves to control the rate of feeding movement of the grinding wheel to produce the desired grinding action on the cheeks adjacent to the ends of the crankpin.

Table tramerse v The work table 40 (Fig. 2) is arranged to be moved longitudinally relative to the machine base on the V-way 4| and the flat way 42. A power operated traversing mechanism is provided comprising a fluid pressure cylinder IIO which is fixed to the base 30. A piston III is slidably mounted within the cylinder H0 and is connected by means of a piston rod 2 which extends in opposite directions from the piston through the opposite ends of the cylinder H0 and is connected to brackets H3 and H4 which are fixed to the table 40.

steadyrest In the grinding of a crankshaft or any long cylindrical piece of work, it is desirable to provide a suitable work steadying rest to steady the work and prevent yibration thereof during the grinding operation. In the grinding of heavy objects, such as crankshafts, it is desirable that the steadyrest be arranged so that it is out of the way during the loading of a work piece or the removal of afinish ground crankshaft from the machine. In the preferred'construction, the steadyrest (Fig. 8) is arranged so that it may be .bodily moved in a vertical direction so that it may be dropped to an inoperative position out of the way for the loading operation. Such a rest may comprise a vertically movable frame I I5 which is provided with a pair of opposed ways I I6 and I II which slide in a vertical slideway I I8 on the front of the machine base. The. upper end of the frame H5 is provided with a horizontally movable work steadylng shoe- IIB which-is artable 40.

pivoted on a stud I38.

, accurately position the work ranged to engage and-steady a crankpin I20 during the grinding operation thereon. The rest shoe I I9 may be adjusted manually in a horizontal direction by means of an adjusting nut |2I so that the steadyrest shoe I I8 may be maintained in operative engagement with the work as it is reduced in size during grinding to steady the same and prevent vibration thereof. Details of the adjustment of the steadyrest shoe I I9 have not been illustrated in the present application since this adjustment is not considered part of the present invention. For further details as to this adjusting mechanism, reference may be had to my prior copending application Serial No. 31,059 filed July 12, 1935, which issued as U. S. Patent No. 2,053,878 dated September 8, 1936.

In order that the frame 5 may be readily raised and lowered to and from an operating position, a fluid pressure mechanism is provided comprising a cylinder I22 which is fixed to the front of the machine base. 'A piston I23 is slidably mounted within the cylinder I22 and is connected by a piston rod I24 with a projection I25 of the steadyrest frame II5. It will be readily apparent from the foregoing description that when fluid is admitted through a pipe I26 into a cylinder chamber I21, the piston I23 will be moved upwardly into the position illustrated in Fig. 8 to raise the steadyrest shoe 9 from the dotted line position IISa into the full line position III], as shown in Fig. 8. Similarly, when fluid under pressure is admitted through a'pipe. I28 into a cylinder chamber I29, the, steadyrest frame II5 will be moved downwardly into the dotted line position, as indicated in Fig. 8, moving the steady rest shoe I I9 down into an inoperative position just above the surface of the work Splash guard.

A grinding operation of this type is usually a wet grinding operation in which a coolant fluid is conveyed onto the grinding wheel and the work piece during the grinding operation, and it is consequently necessary and desirable to provide a splash guard (Fig. 8) to prevent the coolant fluid from being thrown toward the front of the machine on to the operator or the floor adjacent to the machine, In the preferred construction, as illustrated in the drawings, a movable two-part splash guard is provided, comprising an upper splash guard member I which is pivotally mounted on pivot screw I36. The lower end of the upper splash guard I36 rides on the front face of a pivotally mounted splash guard I3I which is The lower end of the splash guard I31 rides on a surface I39 on the table 40. When the steadyrest frame H5 is lowered to an inoperative position, the splash guard I3'I rides down the surface I39 on table 40 which serves to rock the splash guard I31 in a counterclockwise direction. This movement of splash guard I31 serves to also rock the splash guard I35 in a counterclockwise direction until the two guards assume the positions I3'Ia. and I35a, as

. indicated in dotted lines in Fig. 8.

Work table dogging It is desirable to provide a manually operable means for accurately positioning the work table 40 'in a longitudinal direction. A fluid pressure mechanism may be used to rapidly move the table piece relative to steadyinto an approximate position for g'rindingand then a manual adjustment of the table serves to -direction to and the rocking motion of the lever and frame a shaft I41. The gear I46 meshes with a small' gear I46 on the shaft 69. A gear I49 is formed integral with the gear I46 and meshes with a gear I50 rotatably mounted on theshaft I41. In order that the gears I50, gear I49, gear I46, and gear I46 may be rotated to move the rack I46 and the table 40 endwise, a manually operable lever I 56 is pivotally mounted on a stud I56 on 'a bracket. I51 which is fixed on the front of the shaft I41. The lower arm of the lever I55 is provided with a gear segment I56 which meshes with a gear segment I59 formed on the upper end of a yoked member I60 which is pivotally supported on a stud I6I. The yoked member I60 straddles a member I62 with at diametrically opposite points'by means of pins I66 and I64. The member I62 is provided with an internal gear I65 which is arranged to mesh with a portion of the gear I50. In the position of the parts illustrated in Fig. 9, the lever I55 may be rocked to turn the frame I51 on the shaft I41 without transmitting any motion to the table 40. When it is desired to log the table 40 or to move the same endwise, the opthe Jogging lever I55 in a clockwise viewed in. Figs. 3 and 9. This movement serves to rock the yoked member I60 in a counterclockwise direction (Fig. 9) which serves viewed in Fig. 9, I65 into mesh with the gear I50. In this position of the parts, the lever I55 may be rocked in either rock the frame I51 on the shaft I41 .151 is transmitted through the gear I50, the gear I49, the gear I46, gear I46, to move the rack I45 and table 40 to accurately position the work piece relative to the grinding wheel. pressed plunger I61 mounted in a Hydraulic control position successive pins in operative relation with the wheel. It is highly desirable to interlock the table traverse mechanism, the wheel feed mechanism, as well as the work unclamping in order thatthe table cannot be traversed when the wheel is moving toward or from the work or the wheel cannot be fed toward traversing 1 movement to position successive crankpins in operative relation with the wheel. Similarly, it is desirable to interconnect the hydraulic mechanism for unclamping the work piece so that the work piece cannot be unclamped during the infeeding movement of the wheel or during the traversing of the work table. This interlocking is preferably accomplished through the hydraulic system and its controlling valve. In the preferred construction, a pair of fluid port 205, through a I ment of the the cylinder chamber I96 the work during the table pressure control valves (Figs. 2, 22, 23, 24, 25. 26 and 27) are provided, one of which serves to control the admission of fluid to the table traverse cylinder so that either a fast or a slow traverse may be obtained in either direction and a second valve is provided which serves to control the admission of fluid to the wheel feed mechanism, the steadyrest, and the work unclamping mechanism.

As illustrated in the drawings, a valve I which is preferably of the piston type serves to control the admission of fluid to. the cylinder IIO to control the movement of the table 40 either toward the right or toward the left, both at a rapid positioning feed as well as a slow feed for accurately locating the table to position a work piece relative to the operative face of the grinding wheel or for truing the wheel. The valve I15 comprises a valve stem I 16 which is formed integral with a hollow piston member having a central bore I 11 and being provided .with valve pistons I18, I19, I80, I8I, I82, I83,

I64 and I65.

Fluid under pressure is supplied from a reservoir I90 (Fig. 2) within the base 60. A pum I9I drives fluid through a pipe I92 from the reservoir I90 and forces fluid under pressure through a pipe I93 through a port I94 into a valve chamber I95 between valve pistons Ill and I62, In the position of the illustrated in Fig. 22, the fluid under pressure entering the valve chamber I95 is equalized between the pistons I6I and I62 and since the valve is in a neutral position causes no movement of the table 40. When the valve stem I16 is moved into the position illustrated in Fig. 23 to cause a rapid movement of the table 40 toward the left, fluid under pressure entering the valve chamber I95 passes out through a port I96, a pipe I91, into a cylinder chamber I96 to cause the piston III to move toward the left, as viewed in Fig. 2, to cause a corresponding movement to the left of the table 40. During this movement of the table 40, fluid is exhausted from a cylinder chamber I99 through a pipe 200 through a valve port I, a valve chamber 202 between-valve pistons I60 and I6I, through a port 206 into the central aperture I11 within the valve piston I16 and out through a port 204 in the valve I16 through a valve pipe 206, which returns the fluid to the reservoir I90.

When it is desired to slow down the movetable toward the left, as above described, the valve stem I16 is moved toward the left from the position illustrated in Fig. 23 so that the valve pistons assume the positions illustrated in Fig. 24. Fluid exhausting from then passes through pipe 200, port 20I, port 206, into the central aperture I11 in the valve I16 and out through a, port 206, into a valve chamber 209 between the valve pistons I19 and I60, and then out through a port 2I0, a pipe 2, an adjustable throttle or needle valve 2I2 (Fig. '24) and returns to the reservoir through a pipe 2I6. When it is desired to move the table rapidly toward the right, the valve I16 is shifted toward the left, as viewed in Fig. 24, so that fluid under pressure exhausting from the cylinder chamber I96 passes through pipe I61 into a valve chamber 2I5, through a port 2I6, into the central aperture I11 within the valve I16 and passes outwardly through a port 2", a valve chamber 2" between valve pistons I64 and I65, through valve I15, as

- ously unclamp I83 and When it is desired to reduce the fast speed 1 toward the right, as above described, the valve stem I16 is moved so that fluid from the cen tral aperture I11 passes through a port 222, a valve chamber 223 between the valve pistons I84, through a port 222, a pipe 225, and through an adjustable throttle or needle valve 226, and out through a pipe 221 which connects with the pipe 228 to return the fluid to the reservoir W9. By adjusting the needle or throttle valves M2 and 226, the slow speed of the table in either direction may be adjusted to the desired extent.

A second. control valve 239 (Figs. 22, 23, 24, 25, 26 and 2'1) is located directly above the table traversev control valve 1115 and is arranged to control the admission of fluid to the wheel feed cylinder I199, to the steadyrest positioning cylinder M2, and also to the work clamp release cylinders 19 and 15. Fluid under pressure passes from the pump I9I through the pipe I93 to valve I15, and simultaneously passes through a pipe 23I into the valve 239. The valve 239 comprises a movable valve member 232 having formed thereon integral valve pistons 233, 234, 235 and 236. Fluid under pressure passing through the pipe 23I enters a valve chamber 231 between the valve pistons 234 and 235. In the position of the valve member 232, as indicated in Fig. 22, fluid under pressure passes out through a pipe 239 and is simultaneously admitted to cylinder chambers 12 and 11 of the work clamp release cylinders 19 and 15 respectively to simultanethe opposite ends of the work piece. At the same time fluid under pressure is permitted to pass through a pipe 239 and through apipe 249 into a cylinder chamber I29 to move the steadyrest frame II downwardly into an inoperative position. The fluid passing through pipe 239 also passes through a pipe 24I into a cylinder chamber 242 in the wheel feed cylinder I99 to cause the piston 99' to move toward the right, as viewed in Fig. 2, to move the wheel slide 3| and the grinding wheel 32 into their rearward or inoperative positions. In the position of the valve 232 asshown in Fig. 22',

fluid may exhaust from a cylinder chamber 243 in the cylinder I99 through a pipe 244 into a cylinder chamber 245 between valve pistons 233 and 234 and pass outwardly through a port 246 and a pipe 241 which returns the exhaust fluid to the reservoir I99. At the same time, fluid may exhaust from the cylinder chamber I21 in the steadyrest cylinder I22 through a pipe I26 into the valve chamber 245 and out through port 246 and pipe 241 into the reservoir I99.

When a work piece has been loaded into the machine, the valve member 232 is moved into the position illustrated in Fig. 23 so that the valve piston 235 cuts ofi the port 248 and prevents passage of fluid through pipe 238 to the work clamp release cylinders, thereby releasing the tension of the springs 56 and 5I to clamp the work piece in operative relation with the work heads 41 and 48 respectively. In this position of the valve, fluid passing through pipe 23I enters the valve chamber 231 through a port 259 and passes out through a port 25I and pipe 239 into the cylinder chamber 242 of the cylinder I99 and pipe 249 into cylinder chamber I29 of the cylinder I22 to hold the grinding wheel. and the steadyrest in their inoperative positions.

In starting the grinding operation on a crank,- pin, it is desirable to move the grinding wheel into grinding contact with the crankpin to be' ground and to grind ofl the rough spots or any high spots on the pin before the steadyrest is brought into operative engagement with the crankpin being ground. To bring the grinding wheel into operative position toward the work piece, the valve 232 is shifted into the position 11- lustrated in Fig. 26 so that fluid under pressure passing through pipe 23I, through port 259, into valve chamber 231 passes outwardly through a port 255, through the pipe 244, into cylinder chamber 243 to cause the piston 99 to move toward the left, carrying the piston 99, the wheel slide 3I and the grinding wheel 32 into the position of the parts illustrated in Fig. 2. During the forward movement of the wheel slide, fluid is exhausted from the cylinder chamber 242, through pipe 2, pipe 239, through port 25L into a valve chamber 256 between the valve pistons 235 and 236 and out through a port 251 and a pipe 258 into the reservoir I99.

After the grinding wheel 32 and the slide 3i have advanced to the desired extent, the valve 232 is shifted into the position illustrated in Fig. 27 so that fluid under pressure from the pipe 23H entering the valve chamber 231 through port 259 passes out through port 255 and also throu h a port 269 and a pipe I26 into cylinder chamber I21 of the steadyrest positioning cylinder I122 to move the piston I23 upwardly to raise the steadyrest frame II5 into an operative position so that work steadying shoe H9 is in operative relation with the crankpin I29 to be ground. The end chambers 262 and 263 of the valve 239 are provi'ded with ports 264 and 265 respectively which serve to exhaust any fluid leaking by the valve pistons and pocketing in the chambers 262 and 263. Similarly, the end chambers 266 and 261 of the valve I15 are provided with ports 268 and 269 to exhaust any fluid leaking by the valve pistons into chambers 266 and 261 and thereby prevent pocketing of oil in these chambers.

Single co ntrol lever is rotatably supported on the base 39 by means of v a stud 213 so that the main control lever may be swung toward or from the base of the machine about the axis. of the stud 212 as a pivot or may be swung in a direction parallel to the base 39 by movement of the lever about the axis of the stud 213 as a pivot. The valve stem 232 is provided with a sleeve 214 fixed on the outer end of the stem. A rod 215 having slabbed-ofi parallel sides is fixedly mounted on projections 216 of the sleeve 214 and extends in a longitudinal direction relative to the machine base. The lever 219 is provided with a yoked member 211 which straddles the rod 215. It will be readily apparentfrom the foregoing that when the lever 219 is moved toward or from the machine base, pivoting about the stud 212, a corresponding movement of the sleeve 213 and the valve stem 232 to change the to be ground approaches its operative position i position of the valve 230. By moving the lever relativeto the grinding wheel, the control lever 2"! toward or from the base, pivoting it about 210 is moved into position 210d to move the valve the axis of the stud 212, serves to control the I16 in o the position illustrated in Fig. 24 to slow position of the valve 230 to control the work down the movement of the table 30. After the 5 clamp release, the wheel feed, and the steadytable 40 has been moved to positionthe crankpin rest positioning mechanism. The lever 210 is to be ground in operative relation with the grindarranged to be swung in a direction parallel to ing wheel, the control lever 21!! is moved into the base 30 about the stud 273 as a pivot and t position 2109 in which position the table 40 remechanism is so connected that this mov men mains stopped, the steadyrest frame remains 10 f the ver se s o control e Position the down in an inoperative position, and the wheel valve "5 to c nt ol the longitudinad move e slide is in its rearward position. The machine of the work table 40. 'The valve s m is p is then in readiness to bring the wheel forward vided at its outer e d W h a grooved spoolto start the grinding operation. This is accomshap d m r 280 w i h s connected y a pin piished by moving the lever from the posi- 16 "I w th t e long arm a bell crank level tion 210g into the position 210h which serves to m whi h is pivoted on a vertically positioned shift the valve member 2:: into the position 11- stud 284 suppo t d in a bracket on the lustrated in Fig. 26 so that the work table remains chine base 30. The bell nk lever is P stationary, the steadyrest remains down in an idemwit a short arm which is Preferably inoperative position, and fluid is admitted 20 n the f m f 8 D 'fl iii a bushing in through a pipe 2 into cylinder chamber 233 to the lever 210. The P n freely fits Within the move the piston 89 and wheel slide 3i and grindbi-ishiiig so that the level 279 may be moved ing wheel 32 forward into operative engagement toward and from the machine base without with the work After t grinding wheel has changing the position 01' the bell crank level moved forward to the desired extent, the lever 26 When the lever 210 is moved either toward the 21 is hifted from position 21.}; (Fi 6 i t right tward h left, as viewed in F185 1, the 21010 which serves to shift the valve 232 so that bell crank 283 is rocked about its pivot 234 and t l s a e positioned as shown in Fig. 27 so shifts the valve stem to change the Position that fluid is admitted to raise the steadyrest into of the control Valve as to btain either a an operative position with relation to the crank- 80 fast or a slow traversing movement of the table pm being gmumi 33 either in a direction toward the right or to- After the crankmn has been ground t t Ward the km as viewed in F151: depending upon sired extent, the control lever 210 is moved from the posit! the lever position 213]: into position 21% which serves to In order that the movement of the control cause the steadnest to move downwardly w an 35 lever 210 may be rapidly positi n in M inoperative position and to cause the wheel slide different Positmns t0 interlock the move to move rearwardly to its inoperative position.

the and m as The lever :10 may then be shifted either toward trol the traversing movement of the work table, right or toward the left mm positions 319 the feeding movement of the grinding wheel, the or flue depending upon whether it is desired to o positioning movement the steadyrest' and the traverse the table toward the right or toward releasing of the work clamp, it is desirable to the left to position the next crankpm to be Provide a suitable guiding member to control the ground in operative relation with the grinding movements of the lever 210. Asillustrated in Fig. wheel. After the next crankpm has been posh a guide plate is mounted on the base of tioned in operative relation with the wheel, the the machine a and is provided with cross control lever 210 is again moved to position 2100, shaped m therein which serves "strict me into position 210k to hold the work table the movement of the control lever 210 in its stationary while the grinding wheel is fed movement toward and from the machine or 1011- ward toward the work and the steadyrest is gitudinally relative to the machine base. In the moved upwardly into an operative position R18" full line position of the lever 210a, as indicated five to the cmnkpm to be ground in Fi 6, the valves I15 and 230 are in the posi- In order that the mam contmi lever may be Mons illustrated In in which the position located in a predetermined forward position 2107:,

a spring-pressed plunger 332 is mounted in a sure is admitted to work clamp release cylinders bracket on the base L The plunger (Figs. n

In 3 15 to hold the *F in clamped 4 and 7) is provided with an enlarged head which is engaged by a pin 333 on the control lever 210. a work piecehas been inserted in the work hold- The head is provided with a projecting mg a which serves to limit the forward movement of 27012. This movement of the lever shifts the the lever 2" so as to locate it in the forward position 2107:.

ting oil fluid pressure from the work clamp re- Work table locating lease cylinders and allowing the released tension It is desirable to provide a locating device of the clamping springs 5. and to clamp the I (Figs. 1, 4, 5 and 6) for locating the work carwork tpiece in operative position for a grinding rymg table 40 in any one of a plurality of predeopera on.

Then it is desirable to traverse the table 40 to 2:3 3:2 gif ?i igi fiffif gff gifffifi position a crankpin to be BrOiind in operative may comprise a bar 290 fixed on the front of the relation with th s s Wheel This is work table. The bar 290 is provided with a plu- 7 compl shed y moving the lever from the rality of spaced notches 29l which are arranged position 2101: into position 2100, which serves to to be engaged by a pawl :92 on transversely shift the control valve I16 into the position illusmovable indeii'ing plunger 293 which is slidably trated in Fig. 23 so as to cause a fast traversing mounted within a supporting bracket 2 on the movement of the table 40. When the crankpin base of the machine. The plunger is normally 1 lever 291 in a clockwise "located accurately in an axial held in a locating position within one of the notches 29! by means of a spring 295 which is interposed between a portion of the base 39 and the lower end 296 of a pivotally mounted lever 291. The lever 291 is pivotally mounted on a stud 298 and is connected at its 'upper end with a connecting link 299 by means of a pin 399. The other end of the link 299 is connected by kneans of a stud 3! with the outer end of the locating plunger 293. It will be readily appreciated from the foregoing disclosure that the compressed spring 295 exerts a pressure through the lever 291, link 299, to normally urge the locating plunger 293 into engagement with one of the notches 291 in the bar 299. An adjusting screw 392 is' interposed between the lower end 296 of the lever 291 and the end of the spring 295 which serves to permit an adjustment of the tension of the spring 295.

The pawl 292 of the locating plunger 293 remains in engagement with a notch 29! on the bar 299 during the grinding of each crankpin..

After a crankpin has been finish ground, the locating plunger 293 is withdrawn from the notch 29l of the bar 299 when the main control lever 219 is moved in a clockwise direction (Fig. 5)

into a traversing position. A pin 393 on the lever 219 engages the lower end 296 of the lever 291 and rocks it in a counterclockwise direction to move the locating plunger 293 toward the left, as viewed in Fig. 5, to withdraw the pawl 292 from the notch 29l and then permit a traversing movement of the work table.

When the pawl 292 is disengaged from the notch 29l in the bar 299, the control lever 219 is in the position219b (Fig. "6). The lever 219 may then be moved either toward the right or toward the left into positions 219e or 219e depending upon whether. it isdesired to traverse the table toward the right or toward theleft. The table in this position of the control lever moves rapidly in the desired direction and when the next crankpin to be ground approaches a position op'posite'to the operative face of .the grinding wheel, the operator shifts the control lever 219 from the position 2190 or 219e into position 219d or 2191 to slow down the traversing speed of the table 49. The movement of the lever 219 into position 21911 or 219i swings the lever 219 in a oounterclockwise direction (Fig. 5), thereby withdrawing the pin 394 and releasing the tension of the spring 295 which moves the direction and swings the locating plunger toward the right, as viewed in Fig. 5, so that the pawl 292 engages the front surface of the bar. When the table has moved a sufficient distance 'so that the pawl 292 is directly opposite the next notch 29l in the'bar;

299, the released tension of the spring 295 snaps the locating plunger 293 into engagement with the next notch and thereby holds the table against further traversing movement.

Spark splitting The crankshaft tobe ground on a crankpin grinding machine of this type is frequently roughturned in a crank shaft lathe and the pins are not always direction, so that it is diflicult to locate the table 49 by means of a sufficiently accurate spacing bar so that the grinding wheel will grind equally on opposite cheeks of the orankpin at the start of the grinding operation. It is, therefore, necessary to provide a spark splitting or jogging device (Figs. 19, 20 and 21) by which the side grinding of the wheel during the grinding of the cheeks of a crankpin may be readily equalized. In the preferred construction, the-grinding wheel spindle 33 is arranged so that it may slide axially within spindle bearings 394 and 395, so that the wheel may be readily adjusted in an axial direction to equalize the side grinding of the wheel while it is grinding the cheeks of a crank pin. A collar 396 is rotatably mounted on the wheel spindle 33 and has one of its side faces bearing against a shoulder 391 on the spindle 33. A collar 398 holds the sleeve 396 against endwise movement on the spindle. A pivotally mounted yoked member 399 is pivoted on a stud 3H] and connected with the sleeve 396 by means of pins 3| l and 3i2. The yoked member 399 has a rearwardly extending arm 3I3 which is connected by means of a pin 3l4 with a. transversely movable connecting block 3l5 slidably mounted in the head 3l6 of a screw 3". Thescrew 3" is threaded into a rotatable nut 3"! which is held against endwise movement within a depending portion 3l9 of the wheel slide cover. .The outer end of the nut 319 has an integrally formed beveled gear 329 which meshes with a beveled gear 32l on a vertical shaft 322. The shaft 322 carries a gear 323 meshing with a large gear 324 on a stud 325. The stud 325 also supports a gear 326 meshingwith a large gear 321 on the stud 322. The stud 322 also carries a small gear 328 meshing with a gear segment 329 which is fixedly mounted on the lower end of the rotatable shaft 339. A manually operable lever 33! is connected on the upper end of the stud 339 and extends toward the front of the machine so that it may be readily adjusted during a grinding operation. After the work table has been located by means of the spacing bar and locating plunger, the infeeding movement of the grinding wheel is started by pulling the control lever 219 forward into position 219k, as indicated in Fig. 6. This movement starts the forward movement of the wheel. When the wheel engages the work, the side grinding is equalized by moving the spark splitting control lever 33l either toward the right or toward the left, depending upon the grinding relationship between the wheel 32 and the cheeks of the crankpins. Movement of the lever 33I transmits a rotary motion through the gear segment 329, the gear 328, the gear 321, the gear 326, the gear 324, the gear 323, the bevel gear 32l, bevel gear 329, to rotate the nut 3l8 and thereby cause an endwise movement of the screw 3I1 which in turn transmits a rocking motion to the yoked member 399 which moves the grinding wheel spindle in an axial directionto the desired extent so as to split the sparkor equalize the side grinding on the opposite cheeks of a crank pin.

Work stop control slide to an inoperative position, a cam 335 carried by the sleeve 214 engages a roller 336 to open a normally closed limit switch 331. The limit switch 331 breaks the circuit to deenergize a solenoid 338 which is mounted onthe rear of the work head 45. The deenergizing of the solenoid 338 releases the tension of a spring 339 which serves as t to rock a pivotally mounted arm 343 into a dotted line position 3431!, as indicated in Fig. 16, which serves to move the roller 3 carried by a yoked member 342 on the end of a slidably mounted rod 343-, so that the roller 3 may ride upon the periphery. of a cam 344 which is mounted to rotate with the work supporting spindle 51.

.The motor 63 for rotating the work supporting spindles 51 and 52 is preferably of a type which may be controlled by a magnetic reverse starter switch and a motor brake switch so that the rotation of the motor may be stopped in a predeter- .flelds which are controlled by a magnetic starter switch comprising a switch l to control the power field of the motor 353 and a reverse field switch 352 which controls the reversing field of the motor. when the control lever 213 is shifted to stop the work rotation at the end of a grinding operation, the normally closed limit switch 331 is opened by movement of the lever which a motor brake switch 353 to close the magnetic starter switch reverse field 352 which controls the reverse field of the motor 353 to instantaneously reverse the current in the motor and to stop to open the switch from the power field of the motor.

A safety switch 335 is mounted in the power line and serves to render the circuit inoperative in case the current fails. If the electric current supplied to the driving motor 353 fails, the switch 365 opens, and before the work rotation can be movement of'the main control lever 213 from a grinding position 2137:; as Fig. 3, into tion, so that the a position 213b, serves to render the cam 344 and the follower roller 34| operative, so that the motor will be stopped in a predetermined posiwork holder is in an upright or loading position.

Table jogging interlock It is desirable to provide an interlocking mechanism (Figs. 13, 14 and 15) between the main control lever and the table Jogging mechanism. as shown in Figs. 3 and 9, to prevent the table Jogging mechanism from being rendered operative when the table is being traversed by the hydraulically actuated table traverse mechanism. A lever 313 is pivotally mounted on a stud 3" on the base 33. The lower end of the lever is provided with a projecting pin or stud 312 which passes through an elongated slot 313 in the main control lever 213. The width of the slot 313 forms a sliding fit with the square end of the stud 312. The elongated slot together with the square pin or stud 312 permits an in-and-out movement of the control lever toward and from the base without causing any movement of the stud 312 or the lever 313. When the lever 213 is moved in a direction parallel to the table ways, thatis longitudinally relative to the machine base, a movement-toward the right or toward the left of the lever causes the stud 312 to move in a corresponding direction, which serves to rock the lever 313 about its supporting stud 31i as a pivot. A bar 314- is slidably supported in brackets 315 and 316 on the base of the machine. The upper end of lever 313 is provided with a stud 311 which rides in a slot 313 in the bar 314. When the lever 313 is rocked by movementof the main control lever 213, the pin 311 through the slot 313 moves the slide bar 314 longitudinally relative to the base 33. The bar 314 is provided with a relieved portion having a partial cylindrical surface 333 which is of a sumcient radius in the position shown in Fig. 13 to a permit an in-and-out movement of the internal gear I35 so that it may be the gear I53 (Figs. 3 and partial cylindrical surface 333 is no longer concentric with the outer periphery of the member 135. The bar 314 serves to prevent engagement of the internal the 'gear I53 and thus locks the is being traversed hydraulically.

The interlocking mechanism above described also serves to prevent the table from being traversed through a suflicient distance so that the heads 41 or 43 are brought into engagement with the grinding wheel 32. This is preferably accomplished by providing a pair of pins 332 and 333 in the upper surface of the bar 314. arranged to be engaged by a pair 334 and .335 respectively so that when the table These pins are reaches-a predetermined, position -inits longitudinalt'ravel'toward the right, the dog 3. 3.4. engages pin 3l2- and-movesfltlre. bar 3.14 K

as} viewed 'in-Fig'. 13;.Whih se'rves-td rock the lever toward right,

of safety dogsmoves with the wheel slide gages the d ection. During this movement,the pin or stud 312 serves to rock the main control lever 213 in a counterclockwise direction into a neutral or central position to stop the movement of the table 43, and thereby prevent the work head 41 from being broughtinto engagement with the grinding wheel 32. Similarly, when the table lever is moved toward the left, as viewed in Fig. 4, to cause the work table 43 to move toward the left, the safety device above described serves to prevent the table 43 from being traversed through a suflicient distance to bring the work head 43 into engagement with the grinding wheel 32. When the table reaches its extreme left-hand position, a safety dog 335 engaging pin 333 serves to move the bar 314 toward the left, as viewed in Fig. 13, moving the lever 313 in a counterclockwise direction which in turn serves through pin 312 to rock the main control lever 213 in a clockwise direction and thereby shift the control valve and stop the movement of table before the work head 43 is brought into engagement with the grinding wheel 32.

In order to limit the rearward movement of the wheel slide 3! so that the nut 33 cannot run into or engage the projection 393 of the intermediate slide, it is desirable to provide a suitable safety device which serves to stop the rearward movement of the slide when it reaches a predetermined position. It is desirable to cut off the fluid pressure when the wheel slide reaches a predetermined position in'its rearward moveme t. This is preferably accomplished by mounting a normally closed limit switch 39! on the side of the intermediate slide (Fig'. 19'). .The wheel slide 3'! is 313 in a, clockwise provided with a cover plate 392 which is fixed to the wheel slide and extends out and around to enclose the limit switch 39!. The cover plate 392 3! and is provided with an adjustable stop screw 393 which is arranged to engage a roller 394 on the limit switch 39! when the wheel slide 3| reaches a predetermined position in its rearward movement. The limit switch 39! is connected in one side of the power line leading to an electric motor 395 (Fig. 2) which drives the fluid pressure pump !9!. During the normal feeding movement of the grinding wheel 32 either toward or from the work, is normally closed. If the wheel slide 3! moves rearwardly beyond a safe limit, that is beyond a predetermined position, the stop screw 393 enroller 394 on the limit switch 39! and opens the-limit switch, thereby stopping the rotation of themotor 395 and the fluid pump !9!. Stopping of the fluid pump !9! serves to stop the flow of fluid under pressure to the mechanisms of the machine.

Operation The operation of this machine is readily appardisclosure. The crankshaft to be ground is placed in position in the work heads 41 and Y43. The control lever 213 is then moved from position 2130, into position 2131) which serves to relieve the pressure in the work clamp release cylinders 12 and 11 to allow the released tension of the springs 53 and 5! respectively to clamp the opposite ends of the crankshaft in.

driving engagement with the work heads 41 and 48 respectively. The control lever213 is then moved either'toward the right or toward the left to traverse the table' 43 to position" the crankpinto be ground in operative relation with thegrinding wheel.

Y, infeeding movement of the the crankpin The operator shifts thebontr'ol lever 213 from position: 2131)., into eitherposition'213c' or 213e, depending upon the direction it is desired to traverse the table 43 to position the next crankpin to be ground in operative relation with the grinding wheel. This movement of the control lever 213 serves to traverse the table at a fast positioning speed to rapidly bring the crankpin into an operating position. When the crankpin approaches an operating position, the operator shifts the control lever 213 from position 2130 into position 213d or from position 213e into position 213i to slow down the speed of movement of the table 43. When the table positioning plunger or pawl 292 coincides with the notch 29! on the spacing bar 293, the released tension of the spring 295 serves to throw the plunger 292 into engagement with the notch 29! to hold the table in a fixed position for grinding the crankpin. The operator thenmoves the lever 213 through the position 2130 into position 21371. to cause the wheel 32 to move toward the crankpin to be ground. The wheel first approaches the crankpin at a rapid positioning rate and then the dash pot piston I3! is rendered operative to slow .down the grinding wheel to a cheek grinding feed. When the wheel approaches 33! is manipulated to move the grinding wheel spindle 33 axially within its hearings to equalize the grinding on the opposite sides of the wheel 32 as it is fed down the checks of the crankpin so that the spark is split equally between the opposite 'sides of the wheel. This splitting of the spark serves to cause a substantially equal wear on the opposite side faces of the grinding wheel. When the cheeks have been ground to tlfe desired extent, the-hand wheel 94 may be turned to rotate the feed screw 3! to feed the grinding wheel toward the axis of the crankpin to grind the body of the pin to the desiredsize. In the preferred operation of this machine, a dial gauge is utilized which may be pivotally mounted on the wheel guard so that it may be swung into operative engagement with during the grinding thereof so that the hand feed wheel 94 may be rotated to cause an infeeding movement of the grinding wheel while the dial indicator is watched to indicate the size of the piece of work during grinding. When the grinding-wheel engages the body of the crankpin, the control lever is moved from position 21% into position 2131c to admit fluid and cause the steadyrest frame 5 to be raised into an operating position with the steadyr shoe 9 in operative relation with the cran 23. As the wheel 32 engages the body of the pin, the steadyrest adjusting knob !'2! may be adjusted to maintain the shoe us in operative engagement with the pin I23 during the grinding operation to steady the shaft and prevent vibration thereof during the grinding operation.

After the crankpin !23 has been ground to the desired size, the hand wheel 94 is turned to move the wheel rearwardly by an amount equal to or slightly greater than the infeeding movement, and the control lever 213 is simultaneously moved from a poRition 213k into position 2131). This movement 9f the control lever 213 serves to' cause the wheel slide 3! of the grinding wheel 32 to move rearwardly to an inoperative position and causes the steadyrestirame H5 to move. downwardly into an inoperative position,such as that shown in dotted lines in Fig. 8 and in full lines in pending upon the 213e-pr 213e, de direction it. is desired. to -1nove r Fig. lf The. control lever 213 may then be moved from position 2.137) into position next crankpin approaches the grinding position. the control lever 21! is moved into positions 21M or I'lflf'to slow down the speed of the table before the positioning engages the next operations of the era It will thus be seen that there has been provided by this invention apparatus in which the all matter hereinbetore set forth, or shown in I drawings, is to be interpreted as illustrative and not in a limiting sense.

I claim:-

mined loading position.

3. A crankpin grinding 2,161,686 1 tive relation with the grinding wheel. when the I base, a transversely movable wheel slide thereon,

a rotatable grinding wheel on said slide, a longitudinally movable table, opposed rotatable workheads on said table, work clamps on said heads which are arranged to clamp the opposite ends of. a crankshaft in operating position on said head, means including a pair of fluid pressure pistons and cylinders operatively connected go to release said work clamps, a steadyrest arranged to be moved vertically to and from an fluid pressure piston and cylinder to move said steadyrest to and from an operating position, a fluid pressure piston and a cylinder to move the wheel slide transversely either toward or from the crankpin to be ground, means including a fluid pressure piston and cylinder to traverse said table longitudinally to ranged to control the admission of fluid to said wheel slide cylinder to cause the wheel to move either toward or from the crankpin being ground, to admit fluid to said steadyrest cylinder to cause the steadyrest to move either to or from an operating position, to admit fluid to said work clamp release cylinders to unclamp the finish ground crankshaft,

trol lever which is operatively connected 'to actuate both of said control valves.

5. A crankpin grinding machine comprising'a base, a transversely movable wheel slide supported thereon, a rotatable grinding wheel carried by said slide, a longitudinally movable table, opposed rotatable work heads on said table, clamps on said heads which are arranged to wheel to move either towards or from the crankpin being ground, to admit fluid to said steadyrest cylinder to cause the steadyrest to move either to or from an operating position, to admit fluid to said work clamp release cylinder to unclamp the finish ground crankshaft, a control valve arranged to admit 7 fluid to either end or the table traverse cylinder arranged to hold the logging lever in an inoperto traverse the table in either direction at either ative position during the hydraulic table traverse. a fast or a slow speed to position successive 8. A grinding machine comprising a rotatable crankpins in operative relation with the grindgrinding wheel, a transversely movable wheel mg wheel, and a control lever which is operaslide to support said wheel, a longitudinally movtively connected to actuate both of said valves, able work table, means including a fluid pressure said connections being arranged so that when piston and cylinder to traverse said table longithe lever is moved in one direction it serves to .tudinaiiy in either direction, a control valve to actuate the first valve controlling the admisadmit fluid to either end of said cylinder, 9. manusion of fluid to the wheel slide cylinder, the ally operable control lever to actuate said valve, steadyrest cylinder, and the work clamp release a normally inoperative table jogging mechanism cylinder, and when moved in a second direction including a manually operable lever, and an inserves to actuate the second control valve to terlock between said manually operable table jogcontrol the direction and'speed of movement of ging mechanism and said control lever which the work table. serves to prevent movement of the control lever 6. A crankpin grinding machine comprising a and valve when the manual log g mechanism is base, a transversely movable wheel slide, a rotaioperative. able grinding wheel on said slide, a longitudinal- 9. A grinding machine comprising a base, a ly movable table, a pair of opposed, aligned, rorotatable grinding wheel, a transversely movable tatable work heads on said table which are arslide supporting said wheel, a longitudinally movranged to grip the opposite ends of a crankshaft able work table, means including a fluid pressure and tohold the same with successive crankpins in piston and cylinder to move the wheel slide toalignment with the axis of rotation thereof, ward or from the work table, means including a means including a fluid pressure piston and cylin-. fluid pressure piston and cylinder to traverse the der to move the wheel slide transversely toward work table longitudinally. means including a fluid or from the crank'pin to be ground, means inpressure pump and control valve to convey fluid eluding a fluid pressure piston and cylinder to under pressure for said cylinders, an electric momove the table longitudinally to position suecestor to drive said pump, and a limit switch interslve crankpins in operative relation with the posed between the wheel slide and base which grinding wheel, means including an electric m0- is arranged to stop the pump driving motor when tor to synchronously rotate said work holders, the wheel slide reaches a predetermined rearward means including a manually operable control leposition to stop the flow of fluid under pressure ver and a fluid pressure control valve actuated to said cylinders and valve. thereby to control the transverse movement of the 10. A crankpin grinding machine comprising wheel slide and the longitudinal positioning a base, a transversely movable wheel slide, a romovement of the crankshaft, and an electrical tatable grinding wheel carried thereby, a longicontrol apparatus including a motor brake switch tudinally movable table, a pair of opposed aligned which is rendered eflective by movementoi said rotatable work supporting and clamping heads main control lever to stop the work holders in a thereon which are arranged to support a crankpredetermined loading position. shaft, a movable steadyrest, means including a '7. A grinding machine comprising a rotatable control lever to control the movement of the grinding wheel, a transversely movable wheel grinding wheel slide toward and from the crankslide to support said wheel, a longitudinally movshaft support, the longitudinal positioning moveable work table, fluid pressure means including ment of the crankshaft support, the positioning a piston and cylinder to reciprocate said table, a movement of the steadyrest, means including an valve to control the admission otfluid to said electric motor synchronously to rotate said work cylinder to traverse said table longitudinally in heads, and electrical control apparatus for said either direction, a manually operable control lemotor including a limit switch which is actuated ver to actuate said valve, a logging mechanism by and in timed relation with the control lever to arranged to log the work table longitudinally, stop the rotation oi the crankshaft supporting a. manually operable lever to actuate said jogging heads when they are in a predetermined loading mechanism, an interlock between said manually position.

operab e lever and said logging lever which is :r A SILVEN. 

